I'm wanting to take a photo of this light house near me. the only thing is id like the stars in the background to be a start trail. iv a rough idea on how to do this but not 100% i'm thinking set camera to bulb f22 shutter release remote. and take the photo for about 20-30 mins. would this be ok? sadly i don't have an off camera flash as id like to light up the light house.

I'd first take a shot to properly expose the lighthouse. Probably a 10 second guy with an aperture at f/4. Play with the shutter speed until you get it right. THEN, I'd take a series of 30" second, f/4 shots. Camera on continuous high with a wired trigger with the button depressed constantly. Some have this feature built in, others use duct tape and a penny. So for the light trails shots you'd need a whole lot. As many as your battery or card can withstand. I'd then combine the star trail shots with a program like StarStaX... finally I'd blend in the lighthouse with a layered mask in photoshop.

Stacking shorter images is the way to go, along with a single exposure of the lighthouse.
5 mins worth of 30 second exposures will give you much nicer trails than a 5 min exposure, unless you have REALLY dark skies with no light pollution at all.